1. Field of the Invention
The invention relates to a control device that has a circuit board having a heating element, and a motor unit having the control device.
2. Discussion of Background
With reference to FIG. 10, a structure of a conventional control device 300 described in Japanese Patent Application Publication No. 2007-27280 (JP 2007-27280 A) will be explained. The control device 300 includes a circuit board 310 and a housing 320. The circuit board 310 has a first substrate portion 311, a second substrate portion 312, and a connecting portion 313.
The first substrate portion 311 is formed of a rigid substrate. The first substrate portion 311 has heating elements 311A. The second substrate portion 312 is formed of a rigid substrate. The connecting portion 313 is formed of a flexible substrate. The housing 320 has a supporting bottom wall 321 that supports the first substrate portion 311, and struts 322 that support the second substrate portion 312.
In the control device 300, the heating elements 311A are arranged in a space that is sandwiched between the first substrate portion 311 and the second substrate portion 312. Therefore, it is considered that heat of the heating elements 311A is not dissipated easily. However, in JP 2007-27280 A, there is no particular reference to heat dissipation of the heating elements 311A. Hence, the control device 300 has an issue for improvement in heat dissipation of the heating elements 311A.